Range Rover Supercharged Oxygen sensor 3 problem

Range rover supercharged 5.0 2014 (6 oxygen sensors) I have fault on two sensors Bank1 Sensor3 and Bank2 Sensor3 the voltage is high. Oxygen sensors heating (thick wires) is perfect, tested with the bulb.

There are to wires that oxygen sensor is using apart from heating. voltage on one wire of sensor3 is constant 1.2 volts. nothing on the other wire. The same for both sensors 3.
I decided to test Bank1sensor2 on which there was no error. The wire has the same voltage of 1.2 volts, BUT we have ground on the second wire of sensor 2. When starting, on a working sensor 1.2V wire begins to change to 0.6-0.8 which is normal, whereas on both sensors 3 it does not change at all, still the same 1.2.

I checked the wires to the ECU- everything is in perfect.

At the same time, I tried to create a minus on a sensor3 wire where it should be - nothing changed, the voltage 1.2v was still the same on another wire of sensors 3.

Is it ECU or still faulty oxygen sensor? I will be very grateful for your help from people with experience)

Do the o2 sensors react with engine running on live data?

Unlikely to be 2 sensors failed in the same way at the same time.

Mark Piercy said:

Do the o2 sensors react with engine running on live data?

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Only sensors1 and sensors2.
For bank1sensor3 and bank2sensor3 the scan tool showing 1.25V and stays like that on fully warmed up running engine. Voltage measured manually as well. ECU pins in good condition

Shops the maf sensors over and see if the fault moves banks

Three sets of sensors
Jesus wept....
I found this, thermal shock caused by water splashing on the sensors.
There's a solution. Don't drive it in the rain and god forbid this ever goes off road....

What are the actual codes, the heaters on the lambdas can lose their efficiency as they age.

Mark Piercy said:

What are the actual codes, the heaters on the lambdas can lose their efficiency as they age.

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P0144-00 Oxygen sensor- circuit high voltage Bank1 sensor3
P0142 Oxygen sensor Bank 1 sensor 3
P0164 Oxygen sensor- circuit high voltage Bank2 sensor3
P0162 Oxygen sensor Bank 2 sensor 3

Faults don't appear before after a good test drive. If sensors plug disconnected shows no fault.

No faults if the sensors are disconnected?
So when does it fault then?

I'd be tempted to leave them unplugged but not a solution...
So no behavior from them when running... It's not programmed at all is it?

biketeacherdave said:

Shops the maf sensors over and see if the fault moves banks

Click to expand...

I have a problem on 2 banks but thank you for idea)

Mark Piercy said:

No faults if the sensors are disconnected?
So when does it fault then?

I'd be tempted to leave them unplugged but not a solution...
So no behavior from them when running... It's not programmed at all is it?

Click to expand...

not what I am aware of. What i will do probably try and swap sensor2 and sensor3 on the same bank then have a good driving test

Only if they are the same part numbers or this could give false results. Bearing in mind they come out without being destroyed!!

yes indeed, will check the numbers and will try swap plugs only, but still wondering why there are no faults when disconnecting them and check engine on after driving for some time

biketeacherdave said:

Shops the maf sensors over and see if the fault moves banks

Click to expand...

It's the same on both banks according to the OP

russ22 said:

I have a problem on 2 banks but thank you for idea)

Click to expand...

Check for lean codes next these engine suffer badly from vacum leaks which play havoc with the 02 sensors